Sleeve-type carriers are commonly used to package beverage cans and other types of articles, and are typically formed from paperboard blanks which have been folded into sleeve form. Each sleeve is opened by a packaging machine, after which cans or other articles are introduced and the end panels are folded and secured together. The resulting carrier normally has a handle incorporated into the top panel to allow a user to more readily lift and carry it.
Many different handle designs for sleeve-type carriers have come into use over the years. The so-called suitcase type of handle is one, comprising two handle openings in the top panel extending lengthwise of the carrier and being spaced transversely from each other so that the top panel portion between them forms a strap. The carrier is lifted by inserting the fingers in one of the openings and lifting up on the strap portion. Because the edges of the strap are often uncomfortable to the hand of the user, particularly if the package is carried for any length of time, and because the concentration of lifting stresses at the ends of the strap often requires the use of relatively thick paperboard to prevent tearing at these locations, suitcase type handles have been replaced in many cases by transversely extending handles.
A transversely extending carrier handle comprises a transverse opening in the top panel of the carrier through which the fingers of a user are inserted. By then lifting up on the underside of the top panel the package can be lifted and carried quite comfortably. Provision has had to be made, however, for the distribution of lifting stresses in order to guard against tearing at the ends of the handle opening without resorting to the use of thicker paperboard.
To combat the tendency to tear, one type of design incorporates a slit that extends from each end of the handle opening into the adjacent side panel of the carrier. The purpose of the slit is to transfer the lifting stresses from the ends of the handle, where tearing is most likely to occur, to the side panels of the carrier, where they can more readily be absorbed by a relatively large expanse of paperboard.
Heavy loads, for example the weight of twelve beverage cans as opposed to six beverage cans, have pointed up the need for better stress distribution. It has been suggested to include a series of fold lines connecting the ends of the slits to the top panel to transfer lifting stresses back to the top panel. Even this design, however, permits more concentration of lifting stresses adjacent the ends of the transverse slit than desired, and sometimes results in the top panel being pulled up too abruptly when lifted. Other designs making use of additional fold lines in the top panel have been proposed in order to improve stress distribution. These designs, although successful in performance, add to the complexity of the carrier.
In order to provide the necessary lifting stress distribution while simplifying the handle design, it was further suggested to extend the handle opening itself into the side panels of the carrier, with much of the handle opening in the top panel being covered by flaps foldably connected to the handle edges. Lifting stresses were distributed along the arcuate end edges of the handle openings in the side panels. Gaps at the ends of the opening in the top panel provided a quick visual guide to the user as to the location of the handle opening and the manner in which it should be used, and also aided esthetically by providing visual continuity with the handle openings in the upper portion of the side panels. In addition, the narrower free edges of the flaps provided less resistance to movement of the flap past tightly packed underlying cans. Disadvantages of the design, however, are that the gaps do not provide for overall continuity of the colors or other parts of the package graphics and they do not provide for a dust-free environment inside the package. Although the entry of dust or other particles into the interior of a carrier does not affect the contents of the articles within the carrier, its existence does not suggest the image to the consumer that most manufacturers want to present.
It would be desirable to overcome the disadvantages of the latter design without destroying its stress distribution advantages.